Registration Dossier

Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

Administrative data

Endpoint:
toxicity to aquatic algae and cyanobacteria
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Guideline study with acceptable restrictions

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1989
Report date:
1989

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
other: DIN 38412, part L9
GLP compliance:
no

Test material

Constituent 1
Chemical structure
Reference substance name:
2-hexyloxyethanol
EC Number:
203-951-1
EC Name:
2-hexyloxyethanol
Cas Number:
112-25-4
Molecular formula:
C8H18O2
IUPAC Name:
2-(hexyloxy)ethanol
Details on test material:
- Name of test material (as cited in study report): N-Hexylglykol
Purity: no data given

Sampling and analysis

Analytical monitoring:
no

Test solutions

Vehicle:
no

Test organisms

Test organisms (species):
Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)
Details on test organisms:
TEST ORGANISM
- Strain: SAG 86.81
- Source (laboratory, culture collection): Algensammlung Goettingen, Germany

Study design

Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
96 h

Test conditions

Test temperature:
21.6 °C
pH:
7.77 - 7.84 at start
7.55 - 9.15 at termination
Nominal and measured concentrations:
Nominal concentrations. 0, 5, 10, 25, 50, 100 and 250 mg/L
Details on test conditions:
TEST SYSTEM
- Test vessel: no data given
- Initial cells density: ca. 12 000 (N/ml)
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4

GROWTH MEDIUM
- Standard medium used: no data given


EFFECT PARAMETERS MEASURED:
- Determination of cell concentrations: fluorimeter
after 0, 24, 48, 72 and 96 hours


TEST CONCENTRATIONS
- Range finding study
- Test concentrations: 0.5, 5, 50 and 500 mg/L

Reference substance (positive control):
yes
Remarks:
potassium dichromate

Results and discussion

Effect concentrationsopen allclose all
Duration:
96 h
Dose descriptor:
EC10
Effect conc.:
89.323 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Remarks on result:
other: 85.84 - 151 mg/l 95% CL
Duration:
96 h
Dose descriptor:
EC50
Effect conc.:
147.128 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Remarks on result:
other: 76.31 - 283.66 mg/l 95% CL
Duration:
96 h
Dose descriptor:
EC10
Effect conc.:
12.367 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
biomass
Remarks on result:
other: 4.31 - 35.5 mg/l 95% CL
Duration:
96 h
Dose descriptor:
EC50
Effect conc.:
69.617 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
biomass
Remarks on result:
other: 26.87 - 180.36 mg/l 95% CL
Duration:
72 h
Dose descriptor:
EC10
Effect conc.:
23.43 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Remarks on result:
other: 8.71 - 63.03 mg/l 95% CL
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
198.31 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Remarks on result:
other: 40.71 - >500 mg/l 95% CL
Duration:
72 h
Dose descriptor:
EC10
Effect conc.:
11.08 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
biomass
Remarks on result:
other: 4.22 - 29.14 mg/l 95% CL
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
97.58 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
biomass
Remarks on result:
other: 38.05 - 250.26 mg/l 95% CL

Any other information on results incl. tables

Cell density

 Nominal concentrations (mg/L)  0  24 48  72  96 
   (n/ml) (*10^3)   (n/ml) (*10^3)   (n/ml) (*10^3)   (n/ml) (*10^3)      (n/ml) (*10^3)
0   12  41  147  409  918
 5 000   12  48  138  362  928
 10 000   12  47  132  341  911
 25 000   12  46  129  330  918
50 000   12  46  122  274  839
100 000   12  42  91  205  520
250 000   12  26  33  25  19

Cell growth and biomass after 72 h and 96 h respectively

Nominal concentrations (mg/l)  72 h  96 h      
   growth rate   Biomass inhibition (%)  inhibition rate (%)  growth rate    Biomass inhibition (%)   inhibition rate (%)
0   1.18  -  -  1.08 -  -
 5 000   1.09  6.4 -0.2 1.14 6.8  3.5
 10 000   1.08  10.4  0.2  1.12 11.4  5.2
 25 000   1.08  12.0  0 1.10  13.8  6.1
50 000   1.06 23.2  2.1  1.04  22.1  11.4
100 000   0.94  46.5  13.1  0.95  41.8  19.6
250 000 0.11 94.6  89.4  0.24  85.4  79.2

Applicant's summary and conclusion